Over the last century, thousands of people have gone missing. Suddenly and inexplicably, 4400 missing people are returned, all at once, exactly as they were on the day they vanished...
Unclear what this world-altering event means, the government investigates the 4400 to piece together where they've been and why they've been returned. It quickly becomes apparent that their presence will change the human race in ways no one could have forseen.
Season 2 begins one year after the events on Highland Beach revealed that the 4400 were taken and returned by future humans.
NTAC agent Tom Baldwin has been assigned a desk job for the past 12 months, penance for his acts of insubordination despite the fact that those acts were vital in unlocking the mystery behind the 4400.
Kyle, Tom's son, has been living under observation at NTAC, where he has endured numerous tests that have revealed no new information.
Diana Skouris, Tom's old partner, appeals to Nina Jarvis, the new head of the Pacific Northwest Division of NTAC, to reinstate Tom in the field. Diana has also adopted Maia Rutledge as her daughter, unaware that the girl still has precognitive insights.
Meanwhile, Richard, Lily, and their baby Isabelle (now six months old) are living in a mountain cabin, hiding from both Jordan Collier and NTAC.
Collier has become the self-proclaimed figurehead of the 4400, and is on the verge of opening the first "4400 Centre", a place intended not only for fellow returnees but also for regular, everyday people who are looking to 'unlock' the 4400 within themselves.
And Shawn Farrell has left his family behind to become Collier's protégé, using his healing ability to bring in big money contributors to the centre...
A one-hour recap special entitled The 4400: Unlocking the Secrets aired on actionX between the second and third seasons, on 21 February, 2007.
The run of Season 2 on SABC2 was interrupted for three weeks by the Commonwealth Games, When it returned it was moved to the 22h30 timeslot for the remaining episodes.